Each time I travel to central and south Florida and observe the wonderfully flamboyant tropical flora, I am reminded of the unique and frustrating climatic characteristics of Northwest Florida. Our weather is tropical enough through the summer to sustain virtually everything our friends to the south grow, but winters north of the Big Bend are just cold enough to prevent long-term success with most tropical species. However, the genus that is maybe most synonymous with tropical color, the Hibiscus (it even has its own texting emoji!), contains several species that are hardy through our winters. The best landscape plant of these hardy Hibiscus species is creatively (sarcasm) called Hardy Hibiscus or Giant Rose Mallow (Hibiscus moscheutos) and is an absolute star in the Panhandle, bringing the beauty of the tropics to your yard!
Hibiscus ‘Starry Starry Night’ – Photo courtesy Daniel Leonard
Rose Mallow is a native perennial species that occurs in sunny wetlands across the eastern U.S. This species can grow 7-8’ in height in its natural, unimproved state and possesses the largest flowers of any hardy perennial, some varieties easily eclipse 12” in diameter. Rose Mallows bloom through the heat of our long summers and return reliably each winter unfazed by frost. The flowers also happen to be a favorite of butterflies and hummingbirds and bring beneficial wildlife to the landscape. These characteristics and the trend towards the use of pollinator friendly, low-maintenance native perennials in landscapes quickly made Rose Mallow a jewel for plant breeders and now virtually all major horticultural brands have a line of Hardy Hibiscus available at garden centers, in varying sizes, flower color and leaf color/form. Recent breeding efforts have focused on introducing plants with enormous, richly colored flowers held on compact plants with attractive foliage. The results have yielded two series and three individual cultivars that I consider superior selections and are more than worthy of inclusion in your garden:
Summerific® Series by Proven Winners. This series is comprised of four robust (up to 5’ in height) cultivars, ‘Cherry Cheesecake’ (bicolor magenta and white flowers), ‘Berry Awesome’ (purplish lavender flowers), ‘Cranberry Crush’ (a red you really have to see to believe), and ‘Perfect Storm’ (notable for its deep purple foliage).
Luna Series by Monrovia. This series is notable for its ultra-compact (3’ in height or less) size and characteristically large flowers. It is also composed of four cultivars, ‘Luna Red’ (deep red), ‘Luna Blush’ (white, fading to pink near flower margins), ‘Luna Pink Swirl’ (pictured and my favorite, bicolor swirly flowers), and ‘Luna White’ (white with a red center).
Hibiscus ‘Luna Pink Swirl’ – Photo courtesy Daniel Leonard
‘Starry Starry Night’ by Walter’s Gardens. (Pictured) This cultivar combines dark purple to black leaves with swirled pale and dark pink flowers. It has performed very well in my landscape and if I could only grow one, this might be it.
‘Lord Baltimore.’ The classic, large growing cultivar with bright red flowers that is widely available and easily found. An oldie (introduced in 1955) but a goodie.
‘Midnight Marvel’ by Walter’s Gardens. A “hot off the press” new cultivar that is currently difficult to find due to popularity, though some online outlets have them available in small sizes. This one is worth your patience. Sporting deep red blooms on near black foliage, there’s nothing else like it in the landscape.
In addition to being gorgeous plants, Rose Mallows are extremely versatile in the landscape and could not be easier to grow. Because the size varies so greatly (from the diminutive 30” tall ‘Luna’ series to the 8’ tall unimproved species), there really is a place for one in every garden. I like to use the smaller cultivars in large containers to facilitate moving them around where their floral display has the greatest impact or to create a tropical effect where in ground plantings are not an option (pool decks, patios, etc). The larger cultivars make spectacular specimen plantings in perennial and shrub beds and even make a really dense, striking hedge (just know they disappear in the winter). Be sure to give them as much sun as possible, as this will enhance the number of flowers on each plant and darken the foliage on the cultivars with purplish/black leaves. Too little sun will result in fewer flowers and lighter green foliage. As wetland plants, Rose Mallows enjoy regular water, either from rainfall or irrigation; they will let you know when they need it – their large leaves readily wilt under drought stress, somewhat like Hydrangea.
For low-maintenance, native, pollinator friendly, cold-hardy tropical color, you need look no further than Rose Mallow. These perennial shrubs come in all sizes and colors and fit any landscape! Look for the above listed series and cultivars at better garden centers and online retailers and enjoy the oohs and ahhs elicited when people first get a glimpse of Hardy Hibiscus in your landscape! Happy Gardening!
Are you interested in growing squash in your garden? Do you know the difference between summer squash and winter squash? Check out this very informative instructional video on growing squash in your home garden by Walton County Agriculture Agent Evan Anderson.
It’s that time of year. School is out, hurricane season is in, and the mercury is up! Gardens wilt by midday and gardeners retreat into the air conditioning long before then. Unless you have your toes in the water on one of Northwest Florida’s beautiful beaches, it can be a miserable time to be a Floridian, for plants and people! However, despite the relentless heat and blistering sunshine, low-maintenance, eye-catching color can still be had in the landscape. When the calendar flips to June, I turn to my two favorite Florida-Friendly annuals to do the heavy lifting in my landscape: ‘Diamond Frost’ Euphorbia, and the ‘Cora’ Vinca series.
‘Diamond Frost’ Euphorbia – Photo Courtesy Daniel Leonard
A relative newcomer to landscapes, the award winning ‘Diamond Frost’ Euphorbia is an amazing introduction from Proven Winners. The ultimate in tough, ‘Diamond Frost’ does great both as a mounding accent in a container or as a standalone bedding plant in the landscape. Though its individual, teardrop-shaped, white flowers are tiny, the hundreds of them that open each day really pack a floral punch in the landscape! One caveat: if planting in the landscape, I find ‘Diamond Frost’ to be most effective massed in groups of three or more. Due to the daintiness of the flowers, a single plant can get lost among other garden inhabitants. However, when done right, ‘Diamond Frost’ is a proven winner in any landscape!
Mixed container featuring ‘Diamond Frost’ Euphorbia – Photo Courtesy Daniel Leonard
Next, the ‘Cora’ series of Vinca (Catharanthus roseus), also introduced by Proven Winners, is an improvement on an old favorite. Note: This species is also, on occasion, called Periwinkle. However, do not confuse it with the spreading, purple-flowered, perennial groundcover of the same common name! Gardeners in the South have been growing Vincas for years. This species is unbelievably tolerant of harsh conditions, sometimes even seen growing in sidewalk cracks! However, the unimproved species had an Achilles heel: susceptibility to Phytophthora, a devastating fungal rot disease. ‘Cora’ overcomes this issue and is as close to a perfect bedding annual as you’re likely to find. The ‘Cora’ series is composed of cultivars with pinwheel-shaped white, pink and lavender flowers, a color for everyone! The kind (and clever) marketing folks at Proven Winners have even made ‘Cora’ easy to spot on retail nursery benches; just look for the plants in the hot pink containers!
‘Cora’ Vinca Photo: Andrea Schnapp
Both of the above-described plants are extremely undemanding of gardeners. Once established, little is required in the way of irrigation and fertilization. To ensure success, water daily for the first week after planting, back off to a couple of times per week for the next two weeks or so and then watch ‘Diamond Frost’ and ‘Cora’ thrive with only rainfall for the rest of the summer! Keep in mind, during periods of excessive drought, supplemental watering may be required to keep any plant, even drought tolerant ones, looking their best! To meet the minimal nutrition demands of these plants, I incorporate a quality, slow-release fertilizer (for example, Osmocote, Harrell’s Polyon, or any other similar product) at planting. These products last two or three months in our rainy, hot, humid climate and generally need a second application accordingly for full-season performance. ‘Diamond Frost’ Euphorbia and ‘Cora’ Vinca also require full, blazing sun for maximum floral performance. Don’t be shy about siting them in harsh, sunny places, even a few hours of shade tend to make leggier plants that flower less!
Mixed container with ‘Cora’ Vinca accent Photo: Andrea Schnapp
When you need low-maintenance, season long color that can beat the heat, look for ‘Diamond Frost’ Euphorbia and the ‘Cora’ series of Vinca at your local nursery! Stay cool out there folks and happy gardening!
Are you interested in growing lettuce and other leafy greens? Are you looking for tips on extending the growing season for your leafy green crop? If so, then check out this very informative instructional video by Washington County Horticulture Agent Matthew Orwat.
Normally we think of rust as something that deteriorates metal, but a number of different fungal rusts can affect plants in the garden. Rust disease can affect corn plants, cedar trees, and even blueberry bushes. Just like the broad range of plant species that can be plagued by rust, there are a number of species of rust fungal spores floating around and ready to infest your garden. This article will focus on leaf rust of blueberry.
Blueberry leaf rust on the top of a leaf. Photo Credit: Philip Harmon, University of Florida/IFAS Extension.
Leaf rust of blueberry in Florida is caused by the fungus Pucciniastrum vaccinii. Although the common name of the disease is “leaf rust”, the disease can also infect the stems and fruit of blueberry plants. The disease causes small, round spots visible on the tops of leaves. Spots will multiply and the leaves will eventually yellow and fall off. Young stems and green fruit can also become infected as the disease progresses. Bright orange lesions will form on stems and fruit as the thousands of microscopic spores conjoin. The clusters of spores are easily wiped or washed off of plant material. When spores dry out, they become airborne and can be transferred to nearby plants.
Blueberry leaf rust on fruit. Photo Credit: Philip Harmon, University of Florida/IFAS Extension
The rust fungus thrives in hot, humid, wet conditions. A number of cultural practices can be adopted to reduce disease progression and survival.
Irrigation
Disease persistence can be reduced by limiting the amount of water that contacts the plant leaves. Water the base of plants or install drip irrigation for your bushes rather than watering from overhead. If overhead irrigation is the only option, then water plants in the morning rather than in the evening. This allows the leaves to dry out over the course of the day.
Pruning
Removal of approximately 25% of the oldest canes in late winter before spring growth begins will stimulate the production of new canes and should result in plants with canes of different ages and will provide a good mix of vigorous branching and fruit production. Moderate summer pruning can also improve yield and shoot growth. When pruning, cut out vigorous shoots that are growing well beyond the desired canopy height and are in the interior portion of the bush. This will promote a more open growth habit and help with air circulation on the remaining plant material. Some vigorous canes developing from the ground and growing on the outside of the bush can be topped to stimulate branching and flower bud formation.
Mulch
Pine bark mulch helps with establishment of young plants and helps keep soil pH low in existing plantings. A layer of aged pine bark 3 inches deep extending about 2 feet out from the plants will provide a good growing medium for surface feeder roots. Pine straw can be used if pine bark is unavailable. Mulch also moderates soil temperature, helps keep weeds at bay, and adds organic matter to the soil. Make sure to keep mulch raked back about three inches away from the plant canes to provide good air circulation to the roots.
Hopefully this article has given you some tips to have a good blueberry crop for years to come. For more information on growing blueberries in Florida, please visit the University of Florida/IFAS EDIS Publication: Blueberry Gardener’s Guide.
